A float switch with a temperature sensor is a device typically used in tanks or containers to monitor the liquid level while simultaneously measuring the temperature of the medium. It combines two functions in one device: a float switch for level detection and a temperature sensor for temperature measurement. The level is output in the form of a digital signal, and the measured temperature is provided in the form of a resistance signal.
Operation Principle
The operating principle of a float switch based on a Reed contact relies on the use of a Reed contact as a switching element. A float switch consists of a buoyant body, also known as a float, which floats on the liquid surface. The buoyant body is equipped with a magnet. When the liquid level changes, the buoyant body moves up or down accordingly. When it reaches a certain fill level, the magnet approaches the Reed contact. The Reed contact consists of two ferromagnetic contact leaves placed inside a glass bulb. These leaves are separated by a small air gap. When the magnet of the buoyant body reaches the Reed contact, the magnetic field attracts the ferromagnetic leaves and brings them together. This action closes the contact leaves, completing an electrical circuit. This closed circuit can be used to send a signal, such as triggering an alarm or controlling a motor.
Temperature measurement is accomplished using highly accurate temperature sensors of the PT100 or PT1000 type. These sensors utilize the principle of changing the electrical resistance of a metal based on temperature. A PT100 sensor consists of a platinum resistance that changes its resistance value as the temperature increases. Similarly, a PT1000 sensor operates on the same principle, except that its resistance is 1000 times greater than that of the PT100. PT sensors are capable of providing very precise and accurate resistance values directly related to the temperature of the liquid or medium. These analog resistance values are then converted into temperature values and displayed through an appropriate measuring instrument or evaluation circuit. Temperature values can also be transmitted to control and regulation systems to monitor and, if necessary, control and regulate the temperature in the system.
Advantages
- Reliable Level Detection: Float switches are robust and proven sensors for level detection, offering a reliable means of accurately monitoring the level in a tank or container and can be used with various liquids and environmental conditions.
- Accurate Temperature Measurement: Analog temperature measurement provides precise temperature data for the medium in a tank or container, allowing for precise control of process or operating conditions and early detection of potential issues.
- Combined Functionality: The advantage of a float switch with analog temperature measurement is that it can simultaneously monitor two crucial parameters, saving space, costs, and effort by eliminating the need for two separate sensors.
- Easy Installation and Maintenance: Float switches are typically easy to install and require limited maintenance. They have no moving parts inside the liquid container, reducing the possibility of blockages or damage.
- Robust Design: Float switches are often made from durable materials and can be used in demanding industrial environments, including corrosive or aggressive liquids.
- Quick Response: Float switches typically respond rapidly to changes in level or temperature, enabling timely alerts or control.
- Adaptability: Various designs and sizes of float switches are available to meet the diverse requirements of specific applications, enhancing their flexibility.
- Safety: Continuous monitoring of level and temperature helps detect and prevent potential hazardous situations early, improving safety for personnel and facilities.
Applications and Industries
Industrial Automation
In automated manufacturing processes, float switches with temperature measurement are frequently used in fluid tanks and containers to monitor the level and temperature of cooling or lubricating fluids in machinery and process plants, ensuring precise fluid supply for smooth operations and optimal process conditions.
Mechanical Engineering
In machinery and equipment that work with fluids, float switches with temperature measurement are commonly used in hydraulic or lubrication systems. They monitor oil levels and temperature to ensure proper lubrication and cooling of machinery, contributing to extended machine lifespans and reduced downtime due to lubrication issues.
Chemical and Pharmaceutical Industry
In these industries, float switches with temperature measurement are employed in storage tanks and reactors to monitor the level and temperature of chemical substances, allowing for safe chemical handling and controlled reaction conditions.
Power Generation
In power plants and energy storage facilities, float switches with temperature measurement are used to monitor fuel tanks and cooling systems, ensuring efficient power generation and safe operation of facilities.
Food and Beverage Industry
In food processing and beverage production, float switches with temperature measurement are utilized in tanks and containers to monitor the level and temperature of ingredients, products, or cleaning solutions.
Water Treatment and Wastewater Management
In wastewater treatment plants and water purification facilities, float switches with temperature measurement are employed to monitor levels and temperatures in various tanks and basins, ensuring smooth operation of water treatment processes.
